[mytailorisrich]

That's because market prices are what they are, they don't depend on whether it's "gas electricity" or "nuclear electricity".

Now, if you produce electricity by burning gas that you import and gas prices go through the roof then your production costs follow and your stuck.

In the meantime, production costs of nuclear plants have not moved at all. Which makes controlling consumer prices much more doable and less costly, for instance, you can sell that electricity with improved profit margins (and France does export a lot of electricity).